Detection-loophole-free test of quantum nonlocality, and applications

Phys Rev Lett. 2013 Sep 27;111(13):130406. doi: 10.1103/PhysRevLett.111.130406. Epub 2013 Sep 26.


We present a source of entangled photons that violates a Bell inequality free of the "fair-sampling" assumption, by over 7 standard deviations. This violation is the first reported experiment with photons to close the detection loophole, and we demonstrate enough "efficiency" overhead to eventually perform a fully loophole-free test of local realism. The entanglement quality is verified by maximally violating additional Bell tests, testing the upper limit of quantum correlations. Finally, we use the source to generate "device-independent" private quantum random numbers at rates over 4 orders of magnitude beyond previous experiments.